基于单片机的数字式温度计研究

随着时代的发展，数字式温度计在信息、电子、物流等许多领域都被广泛应用。文章阐述了基于单片机技术对普通温度计的改进，通过利用AT8951单片机的强大运算功能，对复杂数据的输入、运算和显示的处理能力进行分析。使数字式温度计在各种检测环境中对温度的监测反应更快、更精确、测量范围更广。     

Donations in a recursive dynamic model

Abstract.  This paper studies how donations respond to unexpected permanent changes in income and tax rates in a recursive dynamic model. The dynamic approach yields several interesting insights. If marginal tax rates are progressive, a permanent jump in a household's income increases its consumption and donations in the short run, but has no effect in the long run. The permanent income elasticity of current donations is likely to exceed one. If the marginal tax rate is flat, the jump in income raises consumption and donations in both the short and the long run. A permanent marginal tax rate cut raises consumption and donations in the long run if marginal tax rates are progressive, while it reduces donations in the short run if it has little direct impact on tax payments. If the marginal tax rate is flat, a tax cut has a positive effect on consumption in both the short and the long run, but has an ambiguous effect on donations.     

STRUCTURE, CONDUCT AND PERFORMANCE ANALYSIS OF THE SOUTH AFRICAN AUTO INSURANCE MARKET: 1980-2000

The traditional structure-conduct-performance framework makes the explicit prediction that market structure determines market conduct, performance and power. The primary goal of this study is to evaluate this prediction using the South African (SA) short-term auto insurance market. The empirical evidence shows that a link between market structure and market conduct, performance and/or power is not present. "Prices" and profits are not statistically significantly related to various sellers' concentration measure and do not follow any explicit trend over time. By construction, profits are directly related to "prices" and follow a cyclical trend, as observed in other countries. A secondary goal of this paper is to compare the findings for the US auto insurance market with the empirical evidence on the SA auto insurance market. While there are few similarities, there is an underwriting cycle in the SA auto insurance market such as is observed for the US auto insurance market.     

Insider trading in credit derivatives

Insider trading in the credit derivatives market has become a significant concern for regulators and participants. This paper attempts to quantify the problem. Using news reflected in the stock market as a benchmark for public information, we find significant incremental information revelation in the credit default swap market under circumstances consistent with the use of non-public information by informed banks. The information revelation occurs only for negative credit news and for entities that subsequently experience adverse shocks, and increases with the number of a firm's relationship banks. We find no evidence, however, that the degree of asymmetric information adversely affects prices or liquidity in either the equity or credit markets.     

STOCK MARKET REACTION TO ANTICIPATED VERSUS SURPRISE RATING CHANGES

I examine whether bond rating changes can be anticipated by investors and test whether the stock price reaction to the eventual change varies as a result. All else equal, the market reaction to changes that could have been easily predicted should be significantly smaller than the reaction to changes that are largely a surprise. Although rating upgrades prove difficult to predict, approximately 20% of downgrades can be correctly predicted using a relatively small number of publicly available variables. There is no significant difference between the stock price reaction to anticipated versus unanticipated rating changes.     

When Are Commercial Loans Secured?

We analyze the factors that influence the decision to secure a commercial loan. We find evidence that variables reflecting adverse selection, moral hazard, and the prospects for default all affect the likelihood a loan will be collateralized. We find no evidence in favor of the predictions of certain theoretical models that high‐quality firms signal by providing collateral. Our results also show that lenders with less risk protection in the form of equity capital are more likely to require collateral, but that banks themselves are less likely to secure loans than nonbanks. Certain loan characteristics also influence the collateralization decision.     

长尾理论经典案例分析

经济的多元化催生出许多新的经济思想，长尾理论可以说是在蓝海战略后又一个有着独到创新的思维。在主流经济的夹缝中成长出的一种新的经济现象。长尾理论并不是一种真正意义上的创造，只是将我们经常忽视的小市场推到了新的舞台。是逆向思维的经典理论。本文着重分析在实际案例中长尾理论的应用。     

International Differences in Student Achievement: An Economic Perspective

Abstract. International comparisons reveal large cross‐country differentials in average student performance. Although there is considerable public debate about these differences, their sources are hardly identified. Using school, teacher and student data from the Third International Mathematics and Science Study (TIMSS), the present paper attempts to explain what causes between‐country gaps in mathematics test score distributions. Following a three‐pronged strategy of micro‐level and cross‐country regressions as well as bilateral country comparisons, we show how these gaps are explained by differences in school, teacher and student characteristics, or financial resources devoted to the school system. Institutional characteristics, such as competition between schools and the composition of the faculty can also help to understand international differences in student achievement.     

Performance of Foreign and Global Mutual Funds: The Role of Security Selection,Region‐Shifting,and Style‐Shifting Abilities

We examine the performance of U.S.‐based foreign and global funds after controlling for their regional and style exposure. We show that, on average, the total performance (TP) and security selection abilities of both foreign and global funds are significantly negative and exhibit short‐term predictability. Additionally, R² reflects funds’ security selection abilities, consistent with previous findings for domestic mutual funds. Investors can earn higher abnormal returns and TP in the short run by purchasing past winners with low R² than by purchasing past losers with high R². However, there is no evidence of predictability in the funds' region‐shifting and style‐shifting abilities.